Alimentación y salud 2006: un laberinto cultural y científico

Al laberinto de la alimentación y la salud se accede por cuatro puertas: la tradición; las dietas regionalistas (mediterránea, Atlántida, de la dehesa); las dietas evolucionistas o paleodietas y la puerta del futuro: los alimentos funcionales, la nutraceútica y la nutrigenómica. En este trabajo se describen las características de estas cuatro alternativas.Elikadura eta osasunaren labirintora lau ateotatik iristen da: tradizioa; eskualdeko dietak (Mediterraneokoa, Atlantidakoa, larrekoa); dieta eboluzionistak edo paleodietak, eta etorkizunaren atea: janari funtzionalak, nutrazeutika eta nutrigenomika. Lan honetan lau aukera horien ezaugarriak deskribatzen dira.On accède au labyrinthe de l'alimentation et de la santé par quatre portes : la tradition ; les régimes régionalistes (méditerranéen, Atlantide, de la «dehesa» (pâturage) ; les régimes évolutionnistes ou paléo régimes et la porte du futur: les aliments fonctionnels, la nutraceutique et la nutrigénomique. On décrit dans ce travail les caractéristiques de ces quatre alternatives.The labyrinth of nutrition and health can be accessed via four doors: tradition; regional diets (Mediterranean, Atlantic, Extremadura); evolutionist diets orpaleodiets and the door to the future: functional foods, nutraceutics andnutrigenomics. This paper describes the characteristics of these four alternatives

Inelastic lifetimes of hot electrons in real metals

We report a first-principles description of inelastic lifetimes of excited electrons in real Cu and Al, which we compute, within the GW approximation of many-body theory, from the knowledge of the self-energy of the excited quasiparticle. Our full band-structure calculations indicate that actual lifetimes are the result of a delicate balance between localization, density of states, screening, and Fermi-surface topology. A major contribution from $d$-electrons participating in the screening of electron-electron interactions yields lifetimes of excited electrons in copper that are larger than those of electrons in a free-electron gas with the electron density equal to that of valence ($4s^1$) electrons. In aluminum, a simple metal with no $d$-bands, splitting of the band structure over the Fermi level results in electron lifetimes that are smaller than those of electrons in a free-electron gas.Comment: 4 papes, 2 figures, to appear in Phys. Rev. Let

Angiofibroma en un individuo de época medieval (s. XII-XIII)

X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200

Características Antropométricas en Atletas de Jiu Jitsu Brasilero de Alto Nivel: Rol del Estilo de Lucha

Indexación: Web of Science; Scielo.SUMMARY: Human performance efficiency and effectiveness in different sports depend to a large extent on the size, weight and proportion of the physique of the athlete. The aim of this study was to identify morphological characteristics of Brazilian Jiu-Jitsu (BJJ) athletes. The sample consisted of 25 highly trained male athletes who were classified according to their fighting style; guard fighter (GF) vs. pass fighter (PF). The athletes were assessed for somatotype, body composition and proportionality. For the whole group of athletes the somatotype was 2.23±0.68, 6.33±1.14, and 1.75±0.87 for endomorph, mesomorph and ectomorph components, respectively. Muscle and adipose tissue percentages were 52.34±2.15% and 19.30±2.51%, respectively. PF were significantly more mesomorph (p< 0.05) and less ectomorph (p< 0.05) than GF. Also, PF had significantly higher phantom Z score for bone mass vs. GF (0.51±0.57 vs. 0.01±0.54; p<0.05), and significantly lower muscle mass- bone mass ratio (4.55±0.31 vs. 4.77±0.56; p<0.05), height (1.71±0.06 vs. 1.77±0.07; p<0.05) and height weight ratio (40.58±1.11 vs. 41.84±1.22). Our results show that morphological characteristics are related to different fighting styles in BJJ athletes.RESUMEN: La eficiencia y efectividad del rendimiento humano en diferentes deportes depende en gran medida del tamaño, peso y proporción del físico del atleta. El objetivo de este estudio fue identificar las características morfológicas de atletas jiu-jitsu brasileros. La muestra consintió de 25 atletas varones altamente entrenados, quienes fueron clasificados de acuerdo a su estilo de lucha; guarderos (GF) vs pasadores (PF). Se evaluó en los atletas somatotipo, composición corporal y proporcionalidad. Para el grupo total de atletas el somatotipo fue 2,23±0,68, 6,33±1,14 y 1,75±0,78 para el endomorfismo, mesomorfismo y ectomorfismo, respectivamente. Los porcentajes de tejido muscular y adiposo fueron 52,34±2,15% and 19,30±2,51%, respectivamente. PF fueron significativamente las mesomorfos (p<0,05) y menos ectomorfos (p<0,05) que GF. Además PF tuvieron una significativamente alto Z score para la masa ósea (4,55±0,31 vs. 4,77±0,56; p<0,05), estatura (1,71±0,06 vs. 1,77±0,07; p<0,05) y relación altura peso (40,58±1.11 vs. 41,84±1.22). Nuestros resultados muestran que las características morfológicas están relacionadas a diferentes estilos de lucha en atletas de BJJ.http://ref.scielo.org/bzhxy

Lifetime of d-holes at Cu surfaces: Theory and experiment

We have investigated the hole dynamics at copper surfaces by high-resolution angle-resolved photoemission experiments and many-body quasiparticle GW calculations. Large deviations from a free-electron-like picture are observed both in the magnitude and the energy dependence of the lifetimes, with a clear indication that holes exhibit longer lifetimes than electrons with the same excitation energy. Our calculations show that the small overlap of d- and sp-states below the Fermi level is responsible for the observed enhancement. Although there is qualitative good agreement of our theoretical predictions and the measured lifetimes, there still exist some discrepancies pointing to the need of a better description of the actual band structure of the solid.Comment: 15 pages, 7 figures, 1 table, to appear in Phys. Rev.

Sensitiveness of the ratio between monovacancy and bulk positron lifetimes to the approximations used in the calculations: Periodic behaviour

Positron lifetimes have been calculated in bulk and monovacancies for most of the elements of the periodic table. Self-consistent and non-self-consistent schemes have been used for the calculation of the electronic structure in the solid, as well as different parameterizations for the positron enhancement factor and correlation energy. The ratio between the monovacancy and bulk lifetimes has been analyzed. This ratio shows a periodic behaviour with atomic number in all the calculation methods and it is in agreement with selected experimental data. The ratio shows, in contradiction to previous assumptions, sensitiveness to the approximations used in the calculations. This extensive work has allowed us to study and enlighten features of the theory and computing methods broadly used nowadays in simulating, studying and understanding positronic parameters.Comment: 6 pages, 4 figures, 4 table

Mercury removal in wastewater by iron oxide nanoparticles

Mercury is one of the persistent pollutants in wastewater; it is becoming a severe environmental and public health problem, this is why nowadays its removal is an obligation. Iron oxide nanoparticles are receiving much attention due to their properties, such as: great biocompatibility, ease of separation, high relation of surface-area to volume, surface modifiability, reusability, excellent magnetic properties and relative low cost. In this experiment, Fe3O4 and γ-Fe2O3 nanoparticles were synthesized using iron salts and NaOH as precipitation agents, and Aloe Vera as stabilizing agent; then these nanoparticles were characterized by three different measurements: first, using a Zetasizer Nano ZS for their size estimation, secondly UV-visible spectroscopy which showed the existence of resonance of plasmon at λmax∼360 nm, and lastly by Scanning Electron Microscopy (SEM) to determine nanoparticles form. The results of this characterization showed that the obtained Iron oxides nanoparticles have a narrow size distribution (∼100nm). Mercury removal of 70% approximately was confirmed by atomic absorption spectroscopy measurements

Somatotype Profile of Professional Male Soccer Chilean Players

Indexación: Web of Science; ScieloRESUMEN: El presente estudio pretende describir el somatotipo del futbolista profesional chileno, así como determinar la variabilidad existente en el somatotipo por posición de juego. Cien jugadores profesionales varones (edad 23±4,4 años), participantes del campeonato nacional de fútbol chileno fueron incluidos en el estudio. Se realizó la medición de 10 variables antropométricas según las normas de la International Society for the Advancement of Kinanthropometry (ISAK). Se calcularon los 3 componentes del somatotipo de Heath-Carter por cada posición de juego. El somatotipo grupal de la muestra estudiada presentó una clasificación de mesomorfo­balanceado (2,25-5,32-2,26), siendo los defensas los con mayor predominio de este componente. La posición con menor dispersión en su somatotipo son defensas y arqueros, mientras que volantes y delanteros presentan mayor variabilidad. En conclusión, a pesar de existir un somatotipo en común, las diferencias en las varianzas entre posiciones de juego entregan información sobre la relevancia de la optimización morfológica en una posición específica de juego. PALABRAS CLAVE: Somatotipo; Antropometría; Fútbol masculino.SUMMARY: The aim of this study was to describe the somatotype of Chilean professional soccer players, and to determine the variability in the somatotype by playing position. One hundred professional male players (age 23±4.4) participants in the Chilean national soccer championship were included in the study. We performed the measurement of 10 anthropometric variables according to the rules of the International Society for the Advancement of Kinanthropometry (ISAK). We calculated the 3 components of the Heath-Carter somatotype for each playing position. The somatotype of the sample group presents a balanced mesomorph classification (2.25-5.32-2.26),especially among defenders. The positions with less dispersion in their somatotype were the defenses and goalkeepers, while the flyers and forwards show more variability. In conclusion, although there is a common somatotype, differences in the variances between playing positions provide information about the relevance of morphological optimization in a playing position. KEY WORDS: Anthropometry; Somatotype; Male soccer.http://ref.scielo.org/v4pdn

The role of occupied d states in the relaxation of hot electrons in Au

We present first-principles calculations of electron-electron scattering rates of low-energy electrons in Au. Our full band-structure calculations indicate that a major contribution from occupied d states participating in the screening of electron-electron interactions yields lifetimes of electrons in Au with energies of $1.0-3.0 {\rm eV}$ above the Fermi level that are larger than those of electrons in a free-electron gas by a factor of $\sim 4.5$. This prediction is in agreement with a recent experimental study of ultrafast electron dynamics in Au(111) films (J. Cao {\it et al}, Phys. Rev. B {\bf 58}, 10948 (1998)), where electron transport has been shown to play a minor role in the measured lifetimes of hot electrons in this material.Comment: 4 pages, 2 figures, to appear in Phys. Rev.